<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
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<script>
    // 箭头函数
var print = function (obj) {
    console.log(obj);
}
var print = obj => console.log(obj);
var sum = function (a,b) {
    return a + b; 
}
var sum = (a,b) => a+b;
//无参函数
let sayHello = () => console.log("hello");
</script>